A friend asks us about his 1998 Chevy Truck saying that it is not starting and died in the street out in front of their home. This is not only a no start problem but it is a situation where the vehicle stopped running pretty much out of nowhere. Luckily he was very near his home so it didn’t require a tow back to their house or to a garage.
This is a problem that many people are going to face. Many times it is simple diagnosis but other times it can be more complex.
The first tool that I suggest every car owner purchase is an ODB Scanner. Newer cars need an ODB2 scanner and much older vehicles with the first generation computers or ones before computer controlled systems can’t make use of a scan tool but there are often ways to diagnose these early computer systems with a blinking dashboard light sequence. You need to know how your vehicle’s computer control system is diagnosed or read and this means you will need to contact your factory dealership and ask or better yet buy a repair manual for your vehicle.
Our friend was able to get the code diagnosed and it pointed to the Ignition Control Module and the person that was helping them also said their distributor might be a problem and because of the miles suggested it be replaced too.
Diagnosing Your Car That Won’t Start
Before we go throwing parts at any car that isn’t starting its important to do basic diagnosis. Although engines today are controlled by computers most of the problems that you have with sensor or other items will normally still allow the engine to run to some extent.
Many things will just cause the engine to run rough or have less performance but there are some things that will just stop an engine from starting.
Engines require three basic things to run. Air from your intake, Fuel and Spark.
Knowing if your engine has enough air is pretty easy. Open your air filter box and look at the filter. If it is loaded with massive amounts of dirt or wet or maybe even oily then you know you have a problem. If it is generally clean then try starting the engine with the air filter out and if it starts and runs all you have to do is replace the filter. This is a real situation and it has happened on vehicles I have worked on more than a few times. Most of the time the filter gets moist and the combination of moisture and dirt impedes all air flow to the engine. Since this is the easiest thing to check you can check this first.
Next you want to see if you have spark. If you happen to have a timing light you can hook it to your spark plug wire and try to start your engine if the light blinks that means voltage is getting to your spark plugs through the spark plug wires. Normally that is enough to exclude the ignition system.
Finally you want to check your fuel system. If you have a fuel filter inside your engine compartment you can remove a line and place the end in a pan or bottle and then crank your engine to start it. Fuel is under a decent amount of pressure and if your fuel filter is not clogged and you have a working fuel pump there should be a good squirt of fuel out of the fuel line. Another option is to use a fuel pressure gauge to read the actual pressure in the system during cranking. The easiest way to know if your fuel pump is working other than opening up a line is to turn your key to the running position and you should hear a whir or hum for about 10 seconds when the key is turned on. This is your fuel pump priming your system with pressure so that it will start quickly when you crank the starter. To tell if your fuel injectors are pumping you want to listen under the hood for a clicking sound while trying to start the engine. Some engines have one injector others have 2 injectors and some systems have an injector for each cylinder in the engine.
These are the three main systems and the quickest ways to check which system is causing the problem. In addition there are many controls, sensors and intermediate devices that you will have to check once you narrow down which system is causing problems
In our friends case the problem was in the ignition control module. The way you check the control module is to find it on your engine near the distributor and turn your key to the run position. Then test if positive voltage is getting to the module. If power is not getting to the module you might have a computer problem or a problem that is telling the computer to shut off power to the module. If you do have power to the module and then you check for spark at the spark plug you either have a bad module or a bad distributor. It is less likely that a distributor will go bad and not cause the car to run really poorly for some time before it goes bad but it is possible it could just die or maybe a capacitor, igniter, or other part needs replacing.In this case the module was bad and it cost about $20 to replace and the engine was running as soon as he could get the part.
Final Note
As a good friend once told me … engines like to run. And this is true for the most part. Even though engines are getting more complex and tighter and harder to work on they are still basically the same engines that were first introduced on cars. They need Air, Gas and Spark to run. Take away any of the three and your engine won’t be happy.
In addition to the tests we went through above there are many others that you might need to perform. Having a copy of the Official Shop Manual and also a copy of a Haynes or Chilton Repair manual for your car is important and it is not much of an investment at about $100 or less considering you will normally make that money back on the first repair you do your self.